Jumpster74

iTrader: (1)

I'm not even really sure where to start troubleshooting with this one, but just took my 95' Miata out for the first drive after over a year of rebuilding it. When I went to switch lanes, I found out that the turn signals now activate the hazards smh. The hazards flash whenever either turn signal is used and they stay lit up when I turn on the headlights.

As far as I know, lights are unrelated to the ECU, but I swapped in an MS3pro from my previous ms2. To my knowledge, I never altered any wiring related to lights, so I'm kind of at a loss on how to track this issue down. How would I go about troubleshooting this?

Padlock

Google the wiring harness diagram for your car and start tracing signals.

Jumpster74

iTrader: (1)

Was actually looking at this earlier today. The only issue is I can't determine where the "flasher unit" is located. Seems like this would logically be the source of the issue or at least where to start testing wires.

Any clue where "Behind left side of I/P" is?

gooflophaze

Instrument Panel.

And I encourage you to hunt down a factory service manual, the wiring diagrams in them are superior to the mellens guides.

Jumpster74

iTrader: (1)

Thank you!

And yes, it's probably about time I find an FSM. The mellens diagrams have given me enough headaches

Padlock

flasher relay is located above the gas pedal under the dash.

Jumpster74

iTrader: (1)

Ok, the more I dig into this, the more I want a punching bag...

So the symptoms are:

• I use either turn signal (turn switch, red) -> All 4 corners flash like hazards + the instrument cluster illumination and both turn signal indicators on the cluster (green) flash
• I turn on running/headlights (headlight switch, blue) -> functions as normal + both turn signal indicators on the cluster illuminate (green)

What has me so completely confused is that the turn switch wiring (red) and headlight switch wiring (blue) are on two separate circuits and seem like they should have no interaction. Somehow the turn and light switches now BOTH control power to the instrument cluster illumination, cluster turn indicators, and all 4 corner indicator light???

I did remove and inspect the flasher unit, but it seemed fine and after looking at diagrams more, I realized the symptoms don't match up with what it controls.

Someone please throw me a hail mary suggestion here before I have to pull the dash to trace wires further

technicalninja

I've had bulb filaments cross inside a 2 filament bulb and cause weird crap.
One at a time disconnect bulbs and see if a change happens. A disconnected turn signal will normally cause fast flashing in that circuit. Make sure it does.
This would normally connect turn/brake and parking light circuits and would not affect the main beams themselves.
The main beams are 2 filaments bulbs as well. A cross here normally makes high/low beam trouble.

And then the ground circuits can be more important than the feed circuits. Sometimes adding extra ground points to a ground circuit solves this kind of stuff.

In the wiring diagram you posted I'd also want to try a new/different flasher unit as it appears the hazard and turn signal circuits come together in the flasher unit only...

A turn signal bulb crossed will power up when the parking lights are turned on and will light up the parking light filaments when the turn signal is turned on.

My money is on a bad bulb first followed by a bad flasher unit then grounds...

Hope this helps!

Let us know what you find

Jumpster74

iTrader: (1)

Wow, never crossed my mind but you nailed it. You'll promptly be receiving a 6 pack next time I'm south of Fort Worth

I feel like a dumbass but completely forgot that I bought and installed a newer style set of TSI's from a local guy about a year back while I was still tearing apart the blown motor.

Looks like the guy switched around the plug wiring for some reason which caused the current to flow the wrong way and into the other circuits on the same ground. Sounds about the same as crossed filaments. Of course, he neglected to mention this when he sold it to me...